Default Transform Objects
QuickDraw GX provides a default transform object for you. When you first create a shape, that shape's transform reference isnil, which means that QuickDraw GX uses the default transform object as that shape's transform. (This assumes that you have not modified the default shape object so that it references a specific transform; see the discussion of default shapes in the chapter "Shape Objects" in this book.)Also, when you explicitly create a transform object, it is initially a copy of the default transform. These are the properties of the default transform object:
QuickDraw GX provides a function that allows you to reset a transform object to these default values at any time. See the section "Manipulating a Transform Object's Owner Count" on page 6-19 for more information.
- A clip shape that is a full shape. No clipping occurs when QuickDraw GX draws the shape associated with this transform; the clip has no effect.
- A mapping that is the identity mapping. When drawing, QuickDraw GX does not change the position, scaling, skewing, rotation, or perspective of the shape associated with this transform; the mapping has no effect.
- A view port list that contains a single default view port that covers all screen view devices. See the chapter "View-Related Objects" in this book for more information on the default view port.
- Hit-test parameters that are
- the default shape-parts mask, in which only the
gxBoundsPartshape part is specified. QuickDraw GX considers the hit successful if the test point falls within the bounding rectangle of the shape associated with this transform.- the default hit-test tolerance, which is 0. The test point cannot be any distance outside of the bounding rectangle if the hit is to be considered successful.
- An owner count of 1.
- An empty tag list.